This invention relates to rotary piston mechanisms, and more particularly to such a mechanism for internal combustion engines, fluid motors, pumps and the like, wherein a rotating piston or rotor confined within a stationary enclosure moves eccentrically with respect to an output or an input drive shaft emanating therefrom.
Rotary piston internal combustion engines exemplified by the Wankel type engine have been designed in many variations. A general summary of such designs may be found in the book "Rotary Piston Machines", by Felix Wankel, published by Iliffe Books Ltd., London, 1965.
The Wankel type engine is generally comprised of a rotating member or rotor of uniform thickness having an outer periphery containing at least two apexes in outerwardmost extension from a center of symmetry, said rotor being housed within a stationary member or stator having two flat sides spaced apart sufficiently to accommodate the rotor, and a circuitous boundary wall perpendicular to said sides, said sides and boundary wall defining a gas-tight enclosure of fixed volume. In operation, the apexes of the rotor are in continuous sliding contact with said boundary wall, thereby defining a confined volume whose magnitude varies with different rotational positions of said rotor. The rotational variation of said confined volume, in association with properly placed ignition means and valves controlling the entrance of fuel vapor and exhaust of combustion gases, simulates the operation of a standard four cycle piston driven internal combustion engine, said cycles being intake, compression, ignition and exhaust. Although the rotary engine affords the inherent advantage of producing rotary torque power without using members undergoing reciprocating motion, difficulties are encountered in maintaining tightly sealed confined volumes. The factor most responsible for leakage is the sliding contact of the apexes of the rotor with the boundary wall of the stator. Said sliding contact also produces wear at the interactive sealing surfaces, said wear being particularly aggravated by the presence of valves in the boundary wall.
The replacement of the valves in the boundary wall with ports which penetrate the flat sides of the stator housing has been disclosed in U.S. Pat. No. 3,966,901 which relates to a rotary piston engine, the stator of which has three curvilinear boundary walls that make sliding contact with the two extremities of a single elongated rotor.
It is accordingly an object of this invention to provide a rotary piston mechanism which minimizes sliding contact between rotor means and other components interactive therewith to define within a stator enclosure confined volumes having magnitudes which vary with the rotational position of said rotor means.
It is another object of this invention to provide a rotary piston mechanism of the aforesaid nature wherein said rotor means is confined within a stator enclosure having two opposed flat sides.
It is a further object to provide a rotary piston mechanism of the aforesaid nature which provides for the controlled passage of gases to and from said confined volumes without employing valves having moving parts.
It is a still further object of this invention to provide a rotary piston mechanism as in the foregoing object capable of providing three power-imparting internal combustion firings within a 360.degree. angular displacement of said rotor means.
These objects and other objects and advantages of the invention will be apparent from the following description.